I want to store my TS101 in my Gridfinity Storage box who has a high of 6u. To make the 3u solder iron holder stackable I have rotate it by 90°.

My iron was sold with an non-slip cap so I add a small space to fit it.

From the Heat Insert I kept only the adapter holder. The fit of the heat inserts are really snug. I use the adapter to push them in the first time.

As I have enough space I added a slot for a replacement tip.